Dalmatian & Yellow Toadflax

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Calophasia lunula
Mecinus janthinus
Rhinusa linariae

Calophasia lunula is a toadflax-feeding noctuid moth which has been released for control of both toadflax species. C. lunula larvae feed extensively on leaves and flowers of toadflax, severely damaging the plants. It is established in Colorado and is available upon request. Large scale impacts on toadflax populations have not yet been documented in Colorado with this biocontrol agent.

Mecinus janthinus is a stem boring weevil that has shown good promise for control of Dalmatian toadflax. This beetle is capable of killing a large portion of the above-ground plant by boring into and killing the stems where the larvae live and feed. These beetles have proven very effective against Dalmatian toadflax at a number of sites around the state. We now have collection sites where we can obtain large enough numbers for redistribution.

The Colorado Department of Agriculture is a member of the International Toadflax Consortium and through the Consortium we have obtained a small population of a root-galling weevil Rhinusa linariae which we will use to establish field insectaries. This weevil has been shown to be effective against yellow toadflax in Canada, so we are hopeful that soon we will have another insect to use against this ever-spreading weed.